The invention relates to a transport diverter for a conveyor for transporting plate material, particularly a roller conveyor. The invention is suitable especially for a flat glass conveyor. However, the invention may also be used in connection with conveyors for other plate materials for example, in the construction field, in the manufacture of dry wall sheets, which are manufactured, like flat glass, on a production line as a continuous plate strip, which is then cut into individual sheets.
During the production of flat glass, the glass from the furnace reaches a conveyor as a continuous strip, which is moved away by the conveyor at a predetermined speed synchronously with the manufacture of the glass strip at the furnace exit. From the point on where the glass strip is sufficiently cooled so as to be sufficiently rigid, the conveyor is a roller conveyor. Along the conveyor, in synchronism with the movement of the glass strip, the glass is optically examined for defects such as enclosures, bubbles, etc., and the defects are marked. The glass strip is cut transversely into different formats generally under the control of a computer and the glass panels cut from the glass strip may also be provided with longitudinal slits. The conveyor includes acceleration sections whereby spaces are formed on the conveyor between subsequent glass panels formed by the transverse cutting.
Subsequently, the flow of the glass panels, which have been cut in transverse direction and provided with slits in a longitudinal direction into different formats so as to eliminate defective areas in an optimal manner and which are therefore on the conveyor as a flow of mixed glass panel formats, is separated onto different conveyor branches by transport or conveyor diverters in order to facilitate the stacking of the glass plates by format sizes. Such transport diverters switch between a first conveyor branch disposed in the plane of the conveyor supplying the glass plates and a second conveyor branch disposed above the first conveyor branch in parallel relationship therewith since the travel direction cannot be changed because of the continuous glass plate flow.
In known glass production lines, such transport diverters are conveyor sections of roller conveyors which are movable between a horizontal operating position in which the arriving glass plates are moved onto the first conveyor branch disposed in the same plane and a ramp-like position in which the conveyor section is inclined from the upstream end of the conveyor section, such that the glass plates are diverted onto the upper second conveyor branch.
However, these known transport diverters in conventional glass production lines are not free of problems. For one, the glass plates move at a substantial speed of about 1 m/sec and the change of direction from the horizontal to the ramp-like raised transport diverter section results in hard impacts at the front edge of an arriving glass plate. And, upon tilting back the ramp-like, raised diverter section to the first transport conveyor branch, which extends in horizontal alignment with the supply conveyer, the glass plate is again subjected to stresses by hitting the horizontal first conveyor branch. As a result, the glass plates may break. The chances of breakage are increased by the fact that the arriving and diverted glass plates are already longitudinally slit so that undesirable breakage may occur particularly in this area. Another problem resides in the fact that the transport diverter section has to have a certain length because its inclination in the ramp-like position thereof is limited and a switchover between the two positions of the transport diverter section is only possible when a glass plate being diverted has left the transport diverter section. This is particularly true for the raising of the transport diverter section into the ramp-like position. Taking into account the time required for the switchover of the transport diverter section, the distance between subsequent glass plates on the conveyor must be greater than the length of the transport diverter section.
It is the object of the present invention to provide an improved transport diverter which avoids the two main problems of conventional transport diverters mentioned above that is the impact on the glass plates and consequently, the chances of damage or breakage and which permits shorter distances between subsequent glass plates on the conveyor than can be allowed with conventional transport diverters. The object is equally applicable to transport diverters for plate materials other than plate glass, for example dry wall plates which are mechanically sensitive and which encounter similar problems during movement on a conveyor.
In a transport diverter for diverting plate material from a supply conveyer to take-off conveyor branches, the transport diverter comprises a series of short conveyor segments, which can be raised in unison for the transfer of a plate from the supply conveyor to a conveyor takeoff branch, which extends at a higher level than the supply conveyer, and which can subsequently be lowered individually one after the other to the level of the supply conveyor as the plate moves off the conveyor segments.
An embodiment of the invention will be described below with reference to the accompanying drawings